MLA

Two Portraits of Missionary Father and Military Officer Leon Bourjade, Papua New Guinea, Ca. 1900-1930. 1900. https://collections.library.yale.edu/catalog/11444308.

APA, 6th edition

Two portraits of missionary father and military officer Leon Bourjade, Papua New Guinea, ca. 1900-1930. (1900). [Photographic postcards (AAT), photographs (AAT), portraits (AAT)]. https://collections.library.yale.edu/catalog/11444308.